how to make a mfc dialog's height unsizeable? -

i playing mfc github project xtrader on github. managed running , having 1 question cannot understand.

this project dialog based mfc based app, main dialog xtraderdlg, when run it, found height of dialog not sizable, width does.

i have being read source quite time , review every place handles setwindowpos() or onsize(). there not traces how done. comment out onsize() or oninitdialog(), height remains unchangeable.

the code has tricks save width , height in config file , reload next time up. believe doesnot matter.

the code has line. ::setwindowpos(m_hwnd, hwnd_topmost, 0, 0, 0, 0, swp_nomove | swp_nosize); remove line result still same. , swp_nosize wont cause height unsizeable. myth me indeed.

can advise me why? main dialog code here.

https://github.com/lpswufe/xtrader/blob/master/xtraderdlg.cpp

this done in ongetminmaxinfo wm_getminmaxinfo.